An apparatus for conveying thick matter, mud, and bulk material of that kind, comprising a thick matter pump, which works preferably with an oscillating motion, a delivery line which is attached to the thick matter pump on the delivery side, and a restraining member, which is arranged in the delivery line and clears the passage, allowing the bulk material to pass through in the delivery line, and blocks it at least partially in the opposite direction.
In an already generally known apparatus of this type, a hydraulically actuated valve plate controlled by the piston travel is arranged at the outlet port of a thick matter pump designed as a single-piston pump. The valve plate releases the outlet port during the piston's pressure stroke and seals it during the suction stroke, so that the bulk material is prevented from flowing back. Apparatuses of this type require a relatively costly control system. Moreover, the service life of the valve plate is inadequate, because the abrasive bulk material subjects the moving slide parts to a considerable amount of wear.
The invention starts from here and is directed to improving the apparatus of the type indicated at the outset in a way that will allow the restraining member to work without controlling means and substantially free of wear.